Bursting Dwarf Galaxies: Implications for Luminosity Function, Space Density, and Cosmological Mass Density
Abstract
The possibility that dwarf irregular and blue compact galaxies undergo episodes of star formation bursts leads to the suspicion that a large fraction of these galaxies remain undetected because of observational selection effects involving limiting magnitude, surface brightness, and angular size. We have attempted to estimate this unobserved fraction by comparing simulated samples of bursting galaxies, constructed using the theoretical results of Gerola, Seiden, and Schulman, with a magnitude-limited catalog of real dwarf and blue compact galaxies. Assuming a frequency distribution of galaxy sizes of the form f(r) = rgamma^, we find that, after correcting the simulated catalog for selection effects, a value of γ = -4.2+/-0.2 gives good agreement with the observed frequency distributions of luminosity, optical radius, and angular size. The same model accounts for the observed luminosity function in the Virgo cluster. The implications of this result for the true shape of the galaxy luminosity function and the contribution to the cosmological density are discussed.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- June 1988
- DOI:
- 10.1086/166408
- Bibcode:
- 1988ApJ...329..618T
- Keywords:
-
- Astronomical Photometry;
- Dwarf Galaxies;
- Galactic Evolution;
- Luminosity;
- Space Density;
- Star Formation;
- Starburst Galaxies;
- Irregular Galaxies;
- Size Distribution;
- Virgo Galactic Cluster;
- Astrophysics;
- GALAXIES: EVOLUTION;
- GALAXIES: PHOTOMETRY;
- GALAXIES: STELLAR CONTENT;
- LUMINOSITY FUNCTION;
- STARS: FORMATION